Signaling system



Dec. 8, 1931. M. G. CROSBY SIGNALING SYSTEM Filed June 14, 1929 INVENTOR MURRAY 6. CROSBY BY ATTORNEY Patented Dec. 8, 1931 UNITED STATES PATENT OFFICE.

MURRAY G. GROS BY, 01E RIVERHEAD, NEW YORK, ASSIGNOR TO RADIO CORPORATION OF AMERICA, A CORPORATION OF DELAWARE SIGNALING SYSTEM Application filed June 14, 1929. Serial No. 370,924.

This invention appertains to a signaling system and especially to a system whereina plurality of geographically spacedcollectors are utilized for receiving purposes.

An object of this'invention is to provide a new and useful method and means utilizing a'plurality of spaced collectors for reducing fading effects at a receiver where the fading consists solely in intermittent diminution of signal strength at each of the geographically spaced points.

According to my invention radio frequency energy is collected at a plurality of geographically spaced points, the energy so collected is separately amplified and subsequently combined; the combined energy is then amplified and a portion of the combined amplified energy is transformed and utilized to vary simultaneously the separate amplification of the energy collected at one of the points and the amplification of the combined energies, thereby maintaining the combined amplified energies constant. The other portion of the combined amplified energies is translated in any suitable fashion.

My invention both as to its organization and method of operation may best be understood by referring to the accompanying drawings in which;

Figure 1 is a block diagram of my fading reducing amplifier allowing of constant volume reception; and Y Figure 2 is a detailed wiring diagram of the arrangement shown in Figure 1.

Turning to Figure 1 radio frequency energy is collected at a plurality of geographically spaced points on antennas 1, 2 of any well known type. The collectors 1, 2 may be made identical or, if desired, may be made so as to have diiferent receiving characteristics- Energy collected on the antennas 1, 2 is amplified by amplifiers A, B and then combined and amplified by means of a common radio frequency amplifier C. A portion of the output of amplifier C is fed into a volume control V which transforms the portion of the combined amplified radio frequency energies fed to it into unidirectional energy. The output of V controls the amplification at points B and C so that the output of am plifier C remains substantially constant regardless of intermittent weakening of the signal at collectors 1 and 2. I

The other portion of the output of common amplifier C is fed into any suitable device such as a radioreceiver R for trans formation and subsequent translation.

i In action, the volumecontrol V controls amplifiers B and C so that the output of C and hence the translated output of receiver R remains constant. Thus when the signal at B decreases and that at A increases the signal from A operates the volume control maintaining the outputof amplifier C" constant. When the signal from A is low and that from B is high the volume control functions on both Band C to maintain constant signal volume from the amplifier C.

When the energy is weak at. both antennas, the volume control B functions to increase the amplification at B and C thereby sensitizing-the Whole system. When the antenna signals are all strong the volume control acts on amplifiers G and B so, as to control the resultant output' In Figure 2 I have shown the electrica' connections for the scheme shown in Figure 1, in detail. Antennas 1, 2 feed into the input sides of electron discharge devices 4;, 6, only the latter of which is volume controlled. The outputs of amplifiers 4, 6 are combined by means oftrans'formers 8, 10 and fed into the input side of amplifier C which is also volume controlled. The amplifiers A, B and G be made of any desired number of stages.

As shown, a portion of the radio frequency output of amplifier G is fed through condenser 12 to a detector or rectifier at V. The other portion of the radio frequency output of amplifier C is fed into receiver R which may be of any well known type.

In the output circuit of the rectifier at V there is'placed an impedance 14: across which potential varies according to the output of amplifier 0. .That is to saygiwhen the input to amplifier 'C is large-the rectified, unidirectional-,-output current of the volume'control detector at vV is large causinga large voltage drop across'impedance 14. As shown this voltage drop is applied to the control electrodes of the amplifier C and electron discharge device 6 so that the outputs therefrom are reduced.

Similarly, when the input of amplifier C is small the current flowing through impedance 14: is small and as a result the biasing potential applied to the control electrodes of the amplifiers at C and B is made more positive, thereby increasing amplification at those points. In this manner the radio frequency energy fed through line 16 into the translating device at R is maintained substantially constant.

Having thus described my invention what I claim is:

1. The method of signaling which includes collecting radio frequency energy at a plurality of geographically separated points, amplifying separately, the energy collected at each point, combining the amplified collected energies, amplifying the combined energies, transforming the combined energy into unidirectional energy, utilizing a portion of the transformed energy to control'the separate amplification of the energy collected at one point and the amplification of the combined energies, and translating another portion of the combined energies.

2. The method of signaling which includes collecting radio frequency energy at a plurality of geographically separated points, amplifying the energy collected at one point, combining the amplified energy, and energy collected at another point, amplifying the combined energies, transforming the combined energy into unidirectional energies, utilizing a portion of the transformed energy to control the amplification of the energy collected at said one point andthe amplification of the combined energies, and translatinganotherportion of the transformed energy.

3. In combination, means for collecting radio frequency energyat a plurality of geographically separated points, means for amplifying separately the energy collected at each point, means for combining the amplified collected energies, means for amplifying the combined energies, means for transforming a portion of the combined radio frequency energy into unidirectional energy, means for utilizing a portion of the transformed energy to control the separate amplification of the energy collected at one point and the amplification of the combined energies, and means for translating another portion of the combined radio frequency energy.

4. In combination, means for collecting radio frequency energy at a plurality of geographically separated points, means for amplifying the energy collected at one point, means for combining the amplified energy and energy collected at another point, means for amplifying the combined energy, means for transforming the combined energy into unidirectional energy, means for utilizing a portion of the transformed energy to control the amplification of the energy collected at said one point and the amplification of the combined energies, and means for translating another portion of the transformed energy.

5. In combination, a plurality of geographically spaced antennas, an amplifier comprising an electron discharge device, having a control electrode, associated with each antenna for separately amplifying the energy collected by each antenna, means comprising another electron discharge device having. a control electrode for combining and amplifying the collected energies, a rectifier for rectifying a portion of the output of said last mentioned device, means for varying the bias, 011 the control electrodes of one of the amplifiers associated with one of said an tennas and the device for amplifying the combined energies, according to the output of said rectifier, and a radio receiver for translating another portion of the output of the device for amplifying said combined energies. I

MURRAY G. CROSBY. 

